Hopkins R S, Stamnes M A, Simon M I, Hurley J B
Division of Biology, California Institute of Technology, Pasadena.
Biochim Biophys Acta. 1988 Jul 29;970(3):355-62. doi: 10.1016/0167-4889(88)90135-8.
Cholera toxin- and pertussis toxin-catalyzed ADP-ribosylation were used to identify and localize G protein substrates in Drosophila melanogaster and in Manduca sexta. Cholera toxin catalyzes ADP-ribosylation of 37 kDa and 50 kDa polypeptides, but these polypeptides are also substrates for an ADP-ribosyltransferase (EC 2.4.2.30) activity endogenous to the Drosophila extracts. Pertussis toxin modifies 37 kDa and 39 kDa polypeptides in Drosophila homogenates. The pattern of proteolysis of the 39 kDa pertussis toxin substrate is similar to that of mammalian Go and is influenced by guanyl nucleotide binding. The 39 kDa Go-like Drosophila and Manduca pertussis toxin substrates are found primarily in neural tissues. These studies provide further evidence that G proteins are present in Drosophila and that this organism can therefore be used to investigate the physiological roles of these enzymes using advanced genetic manipulations.
霍乱毒素和百日咳毒素催化的ADP-核糖基化反应被用于鉴定和定位黑腹果蝇及烟草天蛾中的G蛋白底物。霍乱毒素催化37 kDa和50 kDa多肽的ADP-核糖基化，但这些多肽也是果蝇提取物内源性ADP-核糖基转移酶（EC 2.4.2.30）活性的底物。百日咳毒素修饰果蝇匀浆中的37 kDa和39 kDa多肽。39 kDa百日咳毒素底物的蛋白水解模式与哺乳动物Go相似，并受鸟苷核苷酸结合的影响。39 kDa类似Go的果蝇和烟草天蛾百日咳毒素底物主要存在于神经组织中。这些研究进一步证明G蛋白存在于果蝇中，因此该生物体可用于通过先进的基因操作研究这些酶的生理作用。
